1. Field of the Invention
The present invention relates to a container, and more particularly to an airtight container.
2. Description of the Related Art
Seasoning is usually vacuum packed in tins or canisters for reducing interact with oxygen and atmospheric moisture and thereby maintaining the fresh during an extended period of time prior to the use thereof. Once a consumer opens the vacuum packed container, the vacuum is lost.
The closest prior art of which applicants are aware is their prior U.S. Pat. No. 5,397,024 to Wu et al. The cover includes a valve depressible inward of the cover for allowing air to flow inward or outward of the cover. However, the valve assembly includes a screw secured to the plug rod and engaged with the cover for preventing the valve assembly from disengaging from the cover. The screw is normally made of metal and may not be easily threaded into place. In addition, the screw which is made of metal material may not closely enclose the opening of the cover such that a rubber ring and a gasket are required to be engaged on the screw for engaging with the cover so as to enclose the opening. Furthermore, the inner thread of the plug rod may be easily damaged by the metal screw.